Multiplex joist system

ABSTRACT

The multiplex joist system comprises a series of spaced parallel joists, each having upper and lower hollow tubular chords with webbing therebetween. At regular intervals the hollow tubular chords of the joists are employed as branch supply and return conduits for the various fluids necessary to service the building, such as heating water, cooling water and chilled water. At regular intervals the hollow chords are also employed to carry electrical lines. One chord may be employed for power lines and the other for signal lines. Various utilization devices may be connected between the hollow tubular chords of the various joists so that the fluids will be circulated through such devices. The electrical lines are also connected to the utilization devices. At frequent intervals, the hollow tubular chords are provided with outlet fittings so that connections may be made at virtually any convenient location. The webbing may be in the form of a zigzag member connected to the tubular chords by means of clips which are welded to the chords and also to the webbing. In some cases, the zigzag member may be in the form of a hollow tube adapted to carry fluids.

United States Patent Leonard A. Bihler [72] inventor 25 West 671 JewellRoad, Wheat0n,1ll. 60187 [21] Appl. No. 801,378 [22] Filed Feb. 24, 1969[45] Patented Oct. 12, 1971 [54] MULTIPLEX JOIST SYSTEM 7 Claims, 7Drawing Figs.

[52] US. Cl t. 165/50, 52/220 [51] Int. Cl v. F24f 3/00 [50] Field ofSearch 165/49, 50, 53; 52/220 [56] References Cited UNITED STATESPATENTS 2,425,775 8/1947 Yarborough 165/49 2,729,429 l/1956 Goemann165/49 3,415,024 10/1968 Kotlarz 165/53 Primary Examiner-Charles SukaloAttorneyBurmeister, Palmatier & Hamby ABSTRACT: The multiplex joistsystem comprises a series of spaced parallel joists, each having upperand lower hollow tubular chords with webbing therebetween. At regularintervals the hollow tubular chords of the joists are employed as branchsupply and return conduits for the various fluids necessary to servicethe building, such as heating water, cooling water and chilled water. Atregular intervals the hollow chords are also employed to carryelectrical lines. One chord may be employed for power lines and theother for signal lines. Various utilization devices may be connectedbetween the hollow tubular chords of the various joists so that thefluids will be circulated through such devices. The electrical lines arealso connected to the utilization devices. At frequent intervals, thehollow tubular chords are provided with outlet fittings so thatconnections may be made at virtually any convenient location. Thewebbing may be in the form of a zigzag member connected to the tubularchords by means of clips which are welded to the chords and also to thewebbing. In some cases, the zigzag member may be in the form of a hollowtube adapted to carry fluids.

PATENTED 0m 1 2 IBYl SHEET 1 BF 2 IN VE N T02 Leonard A. Bzhler W WWWMULTIPLEX .IOIS'I SYSTEM This invention relates to a multiplex joistsystem, which not only provides the usual support for ceilings andfloors in a building, but also provides conduits for carrying variousfluids and electrical wiring to all parts of the building.

It is known in the prior art to employ joists of the type having upperand lower chords with a webbing therebetween, which may be in the formof a zigzag rod. .Ioists of this kind are strong yet light in weight.

In accordance with the present invention, the joists not only serve theusual structural function, but also provide conduits for carryingnecessary fluids to all parts of the building. The joists also carryelectrical wiring for both power and signal functions. Thus, each joisthas upper and lower chords in the form of hollow tubes, adapted to serveas conduits for fluids or electrical wiring. A series of the joists arespaced apart at regular intervals. The various necessary fluids arecarried by the hollow tubular chords of the successive joists. Thus, thehollow tubular chords are employed as branch supply and return conduitsfor fluids such as heating water, cooling water and chilled water. Atregular intervals, electrical lines are extended through the hollowtubular chords of one of the joists. One hollow chord may be employedfor power lines, and the other for telephone, sound and other signallines. At frequent intervals, the hollow tubular chords are providedwith fittings which make it easy to connect utilization devices to thechords so that the various fluids will be circulated through theutilization devices. These utilization devices may comprise heating andcooling units, for example. The webbing of each joist preferablycomprises a zigzag member which is secured to the chords by means ofclips, welded to the chords and also to the zigzag member. In some case,these zigzag members may be in the form of a hollow tube adapted tocarry cooling water or other fluids.

Further objects, advantages and features of the present invention willappear from the following description, taken with the accompanyingdrawings, in which:

FIG. 1 is a general perspective view, showing a multiplex joist systemto be described as an illustrative embodiment of the present invention.

FIG. 2 is a fragmentary elevation of one of the joists.

FIG. 3 is a vertical section, taken through one of the joists, generallyalong the line 3-3 in FIG. 2.

FIG. 4 is a perspective view showing one of the clips, employed toconnect the webbing to the tubular chords.

FIG. 5 is a diagrammatic plan view of the multiplex joist system.

FIG. 6 is a diagrammatic elevational section, taken generally along theline 6-6 in FIG. 5.

FIG. 7 is a fragmentary section, similar to a portion of FIG. 3, butshowing a modified joist construction.

As just indicated, FIG. 1 illustrates a multiplex joist system 10comprising a plurality of parallel joists 12, adapted to provide theusual structural support for a floor and ceiling of a building. Thejoists 12 are spaced apart, usually at regular intervals. As shown inFIGS. 5 and 6, the joists l2 normally extend between beams 14 which areparallel to each other but perpendicular to the joists.

Each joist 12 preferably comprises upper and lower chords 16 and 18,together with a webbing 20 connected therebetween. The upper and lowerchords 16 and 18 are the main structural members of the joist 12. Inaccordance with the present invention, the upper and lower chords 16 and18 also act as conduits to carry fluids or electrical wiring. Thus, thechords l6 and 18 are hollow and tubular in form, and preferably are madeof standard metal pipe. Steel is the preferred material, but othermetals may also be employed.

At frequent intervals, the hollow tubular chords 16 and 18 arepreferably provided with tubular stubs or fittings 22 whereby fluidconnections can easily be made to the chords. The stubs 22 are capped orotherwise closed when not used. Electrical wires may also be brought outof the hollow tubular chords I6 and 18 through the stubs 22.

The illustrated webbing 20 is skeletal in form and preferably comprisesa continuous zigzag rod of member 24. However, a number of shorterdiagonal members can also be employed.

The webbing 20 is securely connected to the hollow tubular chords [6 and18. The webbing can be directly welded or it may be preferred to employsleeves or clips 26 to facilitate the connection of the webbing 20 tothe chords 16 and 18. As shown, the sleeves or clips 26 are welded tothe zigzag webbing member 24 and also to the tubular chords 16 and 18.

As shown to best advantage in FIGS. 2-4 each clip 26 preferablycomprises a generally cylindrical sleeve portion 28 which is wrappedpart way around the corresponding chord 16 or 18. The sleeve portion 28is formed with a pair of longitudinal flanges 30 which project laterallyfrom the corresponding chord. The zigzag webbing rod or member 24 istightly received between the flanges 30. As indicated in FIG. 2, weldedjoints 32 are preferably provided between the sleeve portion and thecorresponding chord 16 or 18. Moreover, welded joints 34 are preferablyprovided between the zigzag webbing member 24 and the flanges 30. Theconstruction of the clip or sleeve member 26 is such that it is easy toform the welded joints 32 and 34 by using an electrical resistancewelding machine. Thus, the joists can be fabricated very quickly andeconomically.

The provision of the clips or sleeves 26 makes it possible to usestandard steel pipe for the tubular chords l6 and 18. The use of suchpipe provides adequate strength, as well as ample fluid carryingcapacity and resistance to internal pressure.

As shown in FIGS. 5 and 6, the upper chords [6 of the joists 12 areusually supported on the upper sides of the beams I4. The upper chordsmay be welded or otherwise wise secured to the beams, if desired.Various connecting joints may also be employed. The beams may be eithersolid or similar in construction to the joists.

Normally, there are several beams 14, parallel to one another, andseveral spans of the joists 12, extending between the successive beams.The upper and lower chords I6 and 18 of each joist are normallyconnected to the upper and lower chords of the next joist in theadjacent span, so that the longitudinally aligned joists form continuousconduits for carrying the various fluids and electrical wiring. Variousmeans may be employed to connect the ends of the chords together. Asshown in FIGS. 5 and 6, it is preferred to employ upper and lowerflexible metal conduits 36 and 38 between the ends of the successiveupper and lower chords [6 and 18. For convenience, the flexible conduits36 and 38 may be connected between side stubs 40 projecting from thechords [6 and 18. With this arrangement, the ends of the chords arecapped or otherwise closed. As shown in FIG. 5, the end portions of theupper chords 16 may be overlapped where they rest upon the beams 14.

The successive joists 12 are preferably employed in sequence to handlethe various fluids which need to be circulated throughout the building.One of the hollow chords l6 and 18 of each joist 12 may be employed as asupply conduit for a particular fluid, while the other chord is employedas a return conduit. At regular intervals, one of the joists 12 is alsoemployed to carry electrical wiring. Power lines may be threaded throughone of the hollow chords, while telephone and other signal lines are fedthrough the other chord.

The multiple applications of the joists 12 are illustrated by way ofexample in FIG. 5, in which the successive joists are designated 12(a),(b), (c), (d), (e) and (f). In this case, the upper and lower chords l6and 18 of the first joist 12 (a) are employed as supply and returnconduits for cool water, which may be used to cool light fixtures 42 orother utilization devices. It has been found that the heat generated bylight fixtures is an important part of the air conditioning load of atypical building, and that cooling the light fixtures will reduce thecost of operating the air conditioning system. The chords l6 and 18 ofthe first joist 12(a) are connected to cold water supply and returnpipes 44 and 46, extending transversely across the joist 12 and parallelto the beams 14.

The hollow chords l6 and 18 of the second joist l2(b) are employed tocarry electrical power and signal lines. Thus, the chords are connectedto electrical power and signal conduits 48 and 50, extendingtransversely to the joists. To illustrate the electrical wiring aarrangement, a branch conduit 52 is shown between the light fixture 42and the upper chord 16 of thejoist l2(b) in FIG. 5.

In this case, the upper and lower chords 16 and 18 of the third joistl2(c) are employed as supply and return conduits to carry chilled waterfor the air-conditioning system. Thus, the chords are connnected tosupply and return pipes 54 and 56 for the chilled water. Branch pipes 58and 60 are connected between the joist l2(c) and a terminal unit 62adapted to reheat and recool the room air in the building. In additionto recirculating the room air, the terminal unit 62 receives outside airfor ventilation purposes from a primary air duct 64, which suppliesdehumidified primary air throughout the build ing. The use ofdehumidified primary air throughout the building. The use ofdehumidified primary air permits substantial cooling withoutcondensation problems. Thus, there is no need to insulate the joists orprovide condensate drains. The terminal unit 62 distributes the heatedor cooled air to room outlets 66 through ducts 68.

As shown in FIG. 5, the fourth joist 12(d) is employed to circulate hotwater for heating purposes. Thus, the upper and lower chords l6 and 18of the joist l2(d) are connected to hot water supply and return pipes 70and 72. The hot water is also supplied to the terminal unit 62, by meansof branch pipes 74 and 76, extending between the terminal unit 62 andthe joist l2(d). The terminal unit 62 preferably includes a thermostaticsystem for utilizing either the chilled water or the hot water,according to the temperature of the room air. Such system may include acontrol valve 78, operated by a suitable thermostat. The electricalwiring between the valve 78 and the thermostat may be fed through one ofthe hollow chords 16 and 18 of the joist l2(b), along with other signalwiring. As shown in FIG. 5, a brach electrical conduit 80 is connectedbetween the valve 78 and the joist l2(b).

In FIG. 5, the fifth joist 12(e) is also employed to carry electricalwiring. The sixth joist 12(1) is utilized to circulate cooling water,which may be the same water circulated by the joist 12(a), or water froma different supply. As shown, the upper and lower chords 16 and 18 ofthe joist 120) are connected to the same supply and return pipes 44 and46, as in the case of the joist 12(0), but a separate set of cold waterpipes may be provided.

Another utilization device in the form of a heat pump 82 is suppliedwith water by the joist l2(f). It will be understood that the heat pump82 is adapted to transfer heart from the water to the room air forheating purposes, or to transfer heat from the room air into the waterfor air conditioning purposes. The room air is drawn into the heat pump82 through a duct 84 and is distributed to room outlets 86 through ducts88. Branch supply and return pipes 90 and 92 are connected between theheat pump 82 and the joist 120'). The electrical joist l2(e) may beemployed to carry both the power lines and the thermostat lines for theheat pump 82. Thus, branch electrical conduits 94 and 96, for power andthermostatic lines, are connected between the heat pump 82 and the joistl2(e).

Rather than providing separate sprinkler pipes for fire protection, itis preferred to connect sprinkler heads 98 to the joists which supplythe cooled water and the chilled water. Either type of water, or bothtypes, may be employed. The sprinkler heads 98 are located as needed andare connected to the most convenient hollow chords of the appropriatejoists. In FIG. the sprinkler heads 98 are illustrated as beingconnected to the hollow chords of the joists 12(a), l2(c) and 12(/). Itwill be understood that the sprinkler heads are connected to the chordswhich serve as branch supply conduits for the cold or chilled water.

In the multiplex joist system of the present invention, the joistsprovide structural support for the floors and ceilings of the building.In addition, the hollow tubular upper and lower chords of the joists areemployed as supply and return conduits for the various fluids to bedistributed throughout the building. Such fluids may include hot water,cold water and chilled water. The successive joists are preferablyarranged to carry different fluids, so that all of the necessary fluidswill be conveniently available throughout all parts of the building. Atintervals, the hollow chords of the joists are also employed to carryelectrical power and signal lines.

FIG. 7 shows a modified construction in which the zigzag webbing memberis in the form of a hollow tube or pipe 100, which may also be employedto carry various fluids, such as cooling water. Another advantageousarrangement is to em ploy the hollow webbing tubes 100 to provide fireprotection.

It will be evident that the present invention results in considerableeconomies in the building construction because the multiplex joists takethe place of most of the fluid piping and electrical conduits which arenormally required. Furthermore, the multiplex joist system of thepresent invention insures that all necessary fluids and electricalwiring will be conveniently available throughout the building. In thisway, room arrangements can be changed without any need for costlyrelocation of the fluid piping.

Various other modifications, terminal units alternative constructionsand equivalents may be employed, as will be understood by those skilledin the art.

It is readily possible to prevent corrosion of the joists by the fluidswhich are circulated through the hollow tubular chords. Inasmuch as thefluids are constantly recirculated they soon lose their dissolved orentrained oxygen, so that the fluids become substantially noncorrosive.Moreover, corrosive effects may be inhibited very effectively by usingappropriate additives in the circulating fluids. From the standpoint ofcorrosion control, it is much more advantageous to recirculate water andother fluids through the hollow chords of the joists, than to use thehollow chords for carrying hot or cold tap water, which tends to benoticeably corrosive.

I claim:

1. A multiplex joist system for building construction comprising aseries of horizontally spaced substantially parallel and horizontaljoists,

each joist comprising generally horizontal upper and lower chords spacedapart vertically and with a metal webbing fixed therebetween,

said upper and lower chords being in the form of hollow metal tubes,

said chords and said webbing providing the structural strength andrigidity of said joists,

a system of supply and return pipes for circulating a fluid,

means for connecting said supply and return pipes to the chords of atleast certain of said joists at spaced intervals whereby said chords areutilized as branch conduits for the fluid,

said supply pipe being connected to one chord of each such joist whilethe return pipe is connected to the other chord thereof,

each of said chords having a plurality of laterally projecting stubconnecting devices for selectively establishing fluid carryingconnections thereto,

and a utilization device connected between the upper and lower chords ofat least one such joist whereby the fluid will be circulated throughsaid utilization device,

said utilization device being connected to certain of said connectingdevices.

2. A system according to claim 1,

in which said utilization device comprises means for circulating airthrough said device while utilizing the fluid to change the temperatureof the air.

3. A system according to claim 1,

in which said utilization device comprise means utilizing said fluid toachieve a cooling effect.

4. A system according to claim 1,

including means utilizing said fluid to achieve a heating effeet.

5. A system according to claim I,

power lines while the other chord is utilized for electrical signallines.

7. A system according to claim 1,

in which said webbing includes a hollow continuous tube for carryingfluids.

1. A multiplex joist system for building construction comprising aseries of horizontally spaced substantially parallel and horizontaljoists, each joist comprising generally horizontal upper and lowerchords spaced apart vertically and with a metal webbing fixedtherebetween, said upper and lower chords being in the form of hollowmetal tubes, said chords and said webbing providing the structuralstrength and rigidity of said joists, a system of supply and returnpipes for circulating a fluid, means for connecting said supply andreturn pipes to the chords of at least certain of said joists at spacedintervals whereby said chords are utilized as branch conduits for thefluid, said supply pipe being connected to one chord of each such joistwhile the return pipe is connected to the other chord thereof, each ofsaid chords having a plurality of laterally projecting stub connectingdevices for selectively establishing fluid carrying connections thereto,and a utilization device connected between the upper and lower chords ofat least one such joist whereby the fluid will be circulated throughsaid utilization device, said utilization device being connected tocertain of said connecting devices.
 2. A system according to claim 1, inwhich said utilization device comprises means for circulating airthrough said device while utilizing the fluid to change the temperatureof the air.
 3. A system according to claim 1, in which said utilizationdevice comprise means utilizing said fluid to achieve a cooling effect.4. A system according to claim 1, including means utilizing said fluidto achieve a heating effect.
 5. A system according to claim 1, includingelectrical lines extending through the hollow tubular chords of certainof said joists.
 6. A system according to claim 1, including electricallines extending through the hollow tubular chords of certain of saidjoists, one chord of each such joist being utilized for electrical powerlines while the other chord is utilized for electrical signal lines. 7.A system according to claim 1, in which said webbing includes a hollowcontinuous tube for carrying fluids.